1. Field of the Invention
The present invention relates to a touch panel, and more particularly to a touch panel with a relatively higher yield and a uniform thickness.
2. Description of the Related Art
Touch panels can be classified as capacitive touch panels, resistive touch panels, surface acoustic touch panels, infrared touch panels and the like in terms of touch panel technologies. Among them, the capacitive touch panels and the resistive touch panels take the leading position in market share. The technologies behind the capactive touch panels and the resistive touch panels determine the location of a touched point based on capactive and voltage variation generated at the touched point. Structurally, both touch panels commonly have an upper substrate and a lower substrate. The surfaces of the upper substrate and the lower substrate that face each other have an indium tin oxide (ITO) layer respectively formed on the surfaces to sense the capactive or voltage variation. To output the variation signals, each of the ITO layers is connected with one wire or multiple wires. One end of each of the wires extends to one of the two sides respectively located on the upper substrate and the lower substrate and facing each other. A flexible printed circuit board (PCB) is sandwiched between the upper substrate and the lower substrate and is connected with the ends of the wires to receive signals transmitted through the wires.
However, as the flexible PCB intervenes between the upper substrate and the lower substrate of the conventional touch panels, a thickness of the position where the flexible PCB is inserted between the upper substrate and the lower substrate inevitably increases, thereby causing a non-uniform thickness of the conventional touch panels. Such non-uniform thickness gives rise to adverse effect on the aesthetic appeal of the touch panels' appearance. Besides, gaps are easily formed at the portion of the touch panel at which the flexible PCB is located. Once air penetrates into the touch panels through the gaps, the operational sensitivity of the touch panel is reduced. Hence, the conventional touch panels are further structurally restricted.